Fuel supplying apparatus



Dec. 13, 1938. c. M. BOVARD FUEL SUPFLYI NG APPARATUS Filed June 30, 1937 2 Sheets-Sheet 1 Y 1r||||| [ml H N k\\\\\\\\\\\\\\\\\\\\\\\\\\\\ K V mulini; V/,ml

INVENTOR ATTORNEYS Dec. 13, 1938. c. M. BovARD FUEL SUPPLYING APPARATUS Filed June 30, 1937 2 Sheets-Sheet 2 l INVENTOR ATTO NEYS Patented Dec. 13, 1938 UNITED STATES FUEL SUPPLYING APPARATUS Charles M. Bovard, Mount Vernon, Ohio, as-

signor to Cooper-Bessemer Corporation, Mount Vernon, Ohioa corporation of Ohio Application June 30,

7 Claims.

'I'he invention relates to apparatus for supplying liquid fuel to internal combustion engines, of the type in which a predetermined liquid pressure is maintained in a header from which the fuel is distributed and injected into the cylinders by suitable mechanically operated and timed needle valves. In fuel supplying systems of the above character it has been customary to provide a pressure regulating valve onthe delivery side of the pump, which operated to relieve the pressure when in excess of the pressure for which the valve was set, and also relieved the excess fuel supplied by the pump beyond the needs of the engine. Systems of the above character have given rise to serious operating troubles involving erosion and wear of the valves and their seats, due to the fact that the fuel injection pressure usually runs up into thousands of pounds, and the fuel at this exceedingly high pressure, along with the frequent opening and closing -of the lvalves, acts almost as badly as a solid material in respect to wear and erosion. Numerous efforts have been made over a period of many years to provide a. fuel feeding apparatus which would accurately maintain the desired pressure and avoid the excessive Wear above referred to, but in so far as I am aware prior efforts of the 'above character 1have not performed satisfactorily in actual prac- 1ce.

The present invention aimsto provide a fuel supply apparatus which will avoid excessive wear as above referred to and other attendant objections in fuel supply systems 'of the character under discussion, and which will otherwise satisfy the special operating conditions and requirements met with in supplying fuel to engines of the Diesel type as contrasted to the general art of` pumping liquids. For example and particularly in connection with modern higher speed engines, it is necessary to maintain an exceedingly high delivery pressure on the fuelusually between 5,000 and r1,000 lbs. per sq. in.; and to secure uniform distribution of the fuel, this pressure must be very closely regulated to avoid uctuations which would result in irregular performance of the engine, and yet it is also important that the4 rate of fuel supply be quickly and accurately ad-v justable to conform to changes in load conditions,

which may involve altering the delivery pressure of the fuel (as in the preferred embodiment of the invention hereinafter described) as well as the amount of fuel pumped. 'I'he present invention also markedly reduces the power needed to operate the pump as. compared to Diesel engine .fuel pumps which supplied excess vquantities of 1937, Serial No. 151,118

fuel -by-passed through a heat pressure relief valve as above described, and cuts down the heating of the fuel which was entailed in by-passing it.

In accordance with the present invention the intake of the fuel feeding pump is adjustably throttled in accordance with the pressure existing on the delivery side of the pump, and accordingly the pump plunger may draw in varying amounts of fuel (and produce a partial vacuum) on its suotion stroke, thereby supplying only approximately as much fuel as is needed to maintain the pressure on the delivery side of the pump at the desired amount. With the above mode of operation the regulation of the fuel takes place on the suction side of the pump where high pressures as above referred to are not encountered, and accordingly rapid wear of the regulating parts is avoided; and it becomes unnecessary to provide a valve on the delivery side of the pump from which fuel must escape in regulating the pressure. Preferably, in a more specific aspect of the invention, the throttling effect upon the pump intake is regulated both according to the fuel pressure on the delivery side of the pump, and the lload on the engine, so that the amount of fuel supplied by the pump conforms more closely to both of the above mentioned conditions of operation.

The primary object of the invention accordingly is to provide a fuel supplying apparatus of the above character which will operate reliably to maintain the desired pressure on the delivery side of the fuel pump, and afford long continued service without undue Wear and erosion.

Further objects and advantages will be in part obvious and in part specifically referred to in the description hereinafter contained which, taken in conjunction with the accompanying drawings, discloses a preferred embodiment of the apparatus adapted to operate in accordance withrthe invention; the illustrated form of the invention however should be regarded as merely illustrative of the principles of the invention, in its broader aspects. In the drawings- Fig. 1 is a vertical section of a fuel supplying apparatus constructed to operate in accordance with the invention, the section being taken on vthe lines I-I of Figs. 2 and 3, looking in the direction of the arrows.

Fig. 2 is a side elevation of the apparatus with certain parts cnt away.

Fig. 3 is a transverse section taken on the line 3 3 df Fig. 2, and looking in the direction of the arrows. I

Fig. 4 is a detail view showing more particularly The invention is illustrated as applied to a fuelA pump of the duplex type, involving duplicate pump units, a description of one of which will serve for both. Each pump may be regarded as having a reciprocating pump plunger I (Figs. l and 3) driven by suitable mechanism which will not be described or illustrated in detail since mechanisms suitable for the purpose are known in the art. The pump member or plunger I operates in a pump chamber 2 which is provided with intake openings or ports 3, and a delivery opening 4 (Fig. 1) which latter is closed except during the delivery stroke of the plunger, by valve 5 urged against its seat by a spring 6. During the delivery stroke of the plunger I the valve 5 opens and delivers fuel under high pressure (usually thousands of pounds per square inch) into a delivery passageway 1 (Figs. 1 and 2). From the passageway 1 the fuel under pressure is distributed and injected into the engine cylinders by suitable mechanisms which need not be here described. y

The path of the fuel to the pump chamber 2 appears best in Fig. 3, where a fuel inlet passageway 8 is shown as conducting the fuel through suitable ducts 9 (and a throttling valve construction hereinafter to be described) to a passageway I0 which latter by means of an annular chamber I' is placed in communication with the intake ports 3 of the pump. Accordingly the pump plunge- I during its suction stroke draws in liquid fuel from the passageway 8 through inlated according to the liquid pressure then existingl in the passageway 1; and whenever the liquid i pressure in the passageway 1 rises beyond a predetermined value, the throttling valve is automatically shifted to increase its fuel throttling effect and cause the pump to deliver a reduced amount of fuel to passageway 1. In other words to an extent depending upon the position of the throttling valve, the pump plunger I draws a variable amount of fuel into pump chamber 2, which.

amount will be Iless than a full charge, and will result in the creation of a partial vacuum in chamber 2. Thus the amount of fuel pumped into the delivery passageway 1 and the liquid pressure in such 'passageway may be regulated without resort to pressure regulating relief valves subject to the exceedingly high pressures which exist on the delivery side of the pump. A throttling valve on the pump intake as above described, is not subject to any substantial pressures nor to the attendant erosion above referred to. Consequently the valve will afford long continued use without undue wear, leakage or unreliability in y its action, and moreover adjustment or movement above manner, which is highly important from the standpoint of practical operation` The invention in its broader aspects does not depend upon the use of any particular type of throttling valve, but as shown in Fig. 3 this valve may be made in the form of a rotatable member I2 having an interior fuel receiving chamber I3 which is in communication with the ducts 8 above mentioned and this valve member I2 is provided with throttling ports I4, which afford communication between the chamber I3 and the passageways I0 which vare respectively associated with the two pump units. Referring to Fig. 3 for example, the more the valve member I2 is moved angularly to shift the port I4 toward the right, the greater will be the throttling effect of this port upon the fuel flowing through the inlet ports 3 which are at the left of the figure, and

the greater will be the partial vacuum drawn by the left hand pump plunger I during its suction stroke, and the smaller will be the amount of fuel delivered by the pump during each pressure stroke. (In the form of the invention shown in Fig. 3 a valve sleeve I4a is shown as interposed between the valve member I2 and the passageways I0, but this valve sleeve may be ignored for present purposes.) In like manner as indicated in Fig- 4, the remaining throttling port I4 of valve member I2 serves the pumping unit which is shown at the right of Fig. 3.

In order to adjust the position of the Valve member I2 and its throttling ports I4 to maintain` j valve which shifts its position in response to pressure changes in passageway 1. In the illustrated embodiment of the invention this regulating member I5, as shown more in detail in Fig. l, takes the form of a slide which is pressed by a spring I6 (adjustable as to pressure by stud I1) against a seat I8. Alined slidable plungers I9 and 20 bear against the slide I5, and plunger 20 is exposed to the pressure existing within passageway 1 by reason of the communicating ducts 2I and 22, which may have a fuel strainer23 interposed between them, By adjustment of the .stud I1 the spring I6 will beset at the pressure which it is desired to maintain within the passageway 1, and whenever an excess pressure exists the plungers 20 and I9 will lift the slide I5 against the pressure of spring I 6. Proportionate movement is imparted to the rotatable valve member I2 by suitable means,l such as the rack teeth 24 (Fig. 3) on the slide I5 which mesh with gear teeth 25 on the adjacent end of valve member I2. Thus the valve member I2 and its throti tling ports I4 are adjusted to provide an increased throttling effect on the flow of fuel to the respective pumping units, whenever the pressure on the delivery side of the pump exceeds a predetermined amount.

Fuel regulation of the character above described may be combined with regulation in accordance with the fuel demand of the engine, by providing a second fuel throttling valve of the character above described, in the pathv of fuel flow to the pump. In the illustrated embodiment of the invention the valve sleeve I4a, surrounding the valve member I2, serves this last mentioned purpose. As shown most plainly in Fig. 4 this valve sleeve I4a is provided with throttling ports I4b (similar in character to the ports I4 above de.. scribed) which are interposed between the ports I4 and the passageway IIJ. Depending upon the angular position of the valve sleeve I4a, these last mentioned ports I4b impose a greater or less throttling effect upon the fuel passing into the pumping units.'V The position of the valve sleevev ila may be adjusted by an oscillating arm 21, which latter may be connected to some part on the engine which is adjusted in accordance with the fuel demand, such -as the main throttle of the engine or the governor. As shown in Fig. 5. for example. the oscillating arm 21 may be con- -nected by a link Ila to a' collar 2 la which surposed in the full' inlet tothe pump chamber, and"- ,indicates by the double headed arrows that the position of the throttling valve I2 'isiadjusted according to the pressure in the fuel delivery passageway, andthat the position of the throttling valve Ila is adjuste'd according to the position of some part on the engine, such as the governor 3 ia or main throttle 33, which isadjusted in position according to the fuel demand of the engine. When both throttling valves are employed, the valve lic accordingly modifies the throttling ef fect of valve i2 in' accordance with the fuel demand, thereby facilitating the maintenance of the desired liquid pressure in delivery passageway 7, under different operating conditions. Controls of the above character may be Very readily and quickly adjusted to satisfy differentA operating conditions.

in the construction of apparatus as above-described it is veryadvantageous to reduce to a minimum the volume of the passages' between the throttling valve and the pumpplunger since unduly wide uctuations of iiuid pressure in the delivery passageway 1 otherwise are likelyto occur. However the apparatus may lbe readily built in' the form of a'. compact and self-containedvunit which will avoid the above difllculty,

in order to protectthe apparatus against excessive pressures in the delivery passageway l, in the eventthat the normal4 regulating members above described should fail to function 4fur any reason, I may alsoprovide a pressure relief valve 28 (Fig...2) which is in communication with the delivery passageway 1 through a .duct 2S, The spring 3D which holds' valve 2B closed', Awill normaliy be set to release the valve onlylin the event that the pressure in passageway l builds upV substantially beyondthe normal range.

` Should this happen, valve t28 opens and the excess fuel ypasses through' openings Il into thedrain cup`32. Thus the valve 28 servesonly as an emergency relief and does 'not enter into thek lnormal operation of the apparatus; On the con trary a valuable feature of the apparatus is, as previously explained, that itneeds no pressure regulating valve on the highpressure side of thepump, in normal operation.

the excess relieved from the high pressure delivery line;

While the invention has been described as carried out by an apparatus of specific construction,

it should be understood that many changes may 5 be made therein without departing from the principles of the invention in its broader aspects, within thesc'ope of the appended claims. f

. I claim:

l. Apparatus .for supplying liquid fuel under 1U predetermined pressure `to internal combustion engines; having a pump chamber provided with intake and deliveryopenings, a pump member 'operating insaid'chamber, an adjustable fuel throttling valve in communication with said inl5.

take opening which throttling valve is constructed and arranged to cause the-pump member during suction. strokes to draw in varying amounts of fuel into the pump chamber and produce varying partial vacuum in said chamber accor ing to 0 the adjustment of saidy throttling valve, and

means responsive to fuel pressure changes on the delivery side of the pump for adjusting the position of said throttling valve to regulate the amount of fuel pumped in accordance with Athe fuel pressurevon the delivery side of the pump.

2. Apparatus for supplying liquid fuel under predetermined pressure to internal combustion engines,having a pump chamber provided with intake'and delivery openings, a pump member 30 operating in` said chamber, fuel throttling valve vmembers located in the path of fuel flowingto said pump' chamber, said throttling valve members being constructed and arranged to cause the I. pump member during suction strokes to draw in respectively to fuel pressure changes on the de- 40 livery side of the pump 'and to the fuel demand cf the engine, for adjusting the respective positions of said throttling-valve members to regulate the amount of fuel pumped in accordance` with the fuel pressure on the delivery side of the pump and the fuel demand of the engine.

3. Apparatus for supplying liquid fuel under predetermined: pressure to internal combustion engines,v having a pump chamber provided with intake and delivery openings, a pump member operating in said chamber, fuel throttling valve members in series with each-other and said intake openingsaid throttling valve members being constructed and arranged to cause the pump member during suction strokes to draw in varying amounts of fuel into the pump chamber and produce a' varying partial vacuum in said chamber according to the adjustment of said throttling valve members, and means responsive respectively to-fuel pressure changes on the delivery side of the' pump and to the fuel demand of the engine, for. adjusting the respective positions of said-throttling valve members to regulate the` amount of fuelpumped in accordance with the, fuelp 4. Apparatus for supplying liquid predetermined pressureV to internal combustion engines, having a pump chamber provided with intake and delivery openings, a pump plunger re- 'lo ciprocating in said chamber, a rotatable Vvalve member having a fuel throttling porttherein J which is inkcommunication withfsaidf intake opening which throttling valve is constructed and i arranged to cause the pump member during suc- 7s' e on the delivery side of thepump and c5 :the fuel demand of the engine.

f/uel under tion strokes to draw in varying amounts of fuel into the pump chamberv and pr'oduce a varying partial vacuum in said chamber according to the adjustment 4of said throttling valve, said'apparatus having a fuel delivery passageway leading from said delivery opening and a regulating mem-` ber for said `valve which is movable in position according to the liquid pressure existing in said delivery passageway, means being provided to adjust the angular position of said valve member in response to changes-in position-of said regulating member to regulate' the amount of fuel pumpedv in accordance with the fuel pressure on the delivery side ofthe pump.

'5. Apparatus for supplyingy liquid fuel under predetermined pressure to internal combustion engines, having a pump chamber provided with y intake VVand delivery openings, a pump plunger reciprocating in said chamber, a rotatable valve member having a fuel throttling port therein which is in communication-with said intake opening, said apparatus having' a fuel -delivery passageway leading from said delivery opening'and a regulating member for said valve member which is movable in position according to the liquid pressure existing in said delivery passageway,

means being provided to adjust the angular position of said valve member in response to changes'in position of said regulating member, a rotatable valve sleeve enclosing said first mentioned valve member and also provided With a fuel throttling port interposed between the first mentioned port and the intake opening, said valve member and valve sleeve being constructed and arranged to cause the pump member during sucworking in said chamber, a throttling valve member positioned to control the flow of fuel to said intake opening which throttling valve member is constructed and arranged .to cause the pump member during suction strokes todraw in varying amounts of fuel into the pump chamber and produce-a varying partial vacuum in said chamber according tothe adjustment of said throttling valve member, said apparatus having a fuel delivery passageway leading from .said delivery opening and a regulating member for said valve member which is movable in position according to the liquid pressure' existing in said delivery passageway, means being provided to adjust the position of said valve member ink response to changes in position of said regulating member to regulate the amount of fuel pumped in accord-- ance with the fuel pressure on the delivery side of the pump. Y

7. Apparatus for supplyingvliquid fuel under predetermined pressure to internal combustion engines having a pump chamber provided with' intake and delivery openings, a pumpmember working in said chamber, a throttling valve member positioned to control the iiow of fuel to said intake opening, said apparatus having a fuel delivery passageway leading from said delivery opening and a regulating member for said valve member which is movable in position according to the liquid pressure existing in said delivery passageway, means being-provided to adjust the position of said valve member in 'response to changes in position of said regulating member, a second throttling valve member also positioned to control the flow' of. fuel to said intake opening,

said throttling valve members being constructed and arranged to cause the pump member during suction strokes to draw in varying amountsv of fuel into the pump chamber and produce a varying partial vacuum in said chamber according to the adjustment of said throttling valve members, and means whereby the position of said second mentioned throttling valve member may be adjusted in response to changes in the fuel demand of the engine.

CHARLES M. BOVARD. 

